Field
This document relates to a narrow bezel flat panel display, and more particularly to a narrow bezel flat panel display where a space in which a connection member disposed along one end of a thin film transistor substrate is removed.
Related Art
There have been rapid developments in display devices, which include flat panel display devices (FPDs), which are thin and light, and capable of being manufactured to be large-area flat panel displays, and are used to replace a cathode ray tube (CRT) having bulky volume. Examples of the FPD include a liquid crystal display device (LCD), a plasma display panel (PDP), an organic light emitting display device (OLED), an electrophoretic display device (EPD), and the like, among which the LCD displays images by controlling electric fields applied to liquid crystal molecules according to a data voltage. An active matrix type LCD, which may be manufactured with low costs and high performance achieved by the development of processing and operating technologies, is most widely used in applications of almost all display devices ranging from small mobile devices to large televisions.
Recently, with an increasing demand for a flat panel display and with the development of the flat panel display technology, there have been various demands regarding external designs of the LCD from an aesthetic point of view, including an increasing demand for a flat panel display with a reduced bezel area.
As a way of reducing a bezel area, a printed circuit board (PCB) may be disposed on the rear surface of a display panel to thereby reduce a non-display area of the display panel. Hereinafter, a structure of a general liquid crystal display is described by reference to FIGS. 1 and 2. FIGS. 1 and 2 are diagrams illustrating a structure of a general liquid crystal display.
As illustrated by FIG. 1 and FIG. 2, a general LCD includes a display panel LCP, a backlight unit BLU that emits light to the display panel LCP, and a driving unit that drives the display panel LCP.
The display panel LCP includes a thin film transistor substrate TFS on which a display area AA and a non-display area NA are defined, a color film substrate CFS that is disposed on an upper surface of the AA, and a liquid crystal cell LC that is interposed between the thin film transistor substrate TFS and the color film substrate CFS as illustrated by FIG. 2.
A color filter having a pattern of red, green, and blue, or having a pattern of red, green, blue, and white is formed on the color filter substrate CFS. In addition, a black matrix may be further formed thereon.
A plurality of gate lines that are arranged in one direction and a plurality of data lines that are arranged in a direction perpendicular to the gate lines are formed on the thin film transistor substrate TFS. Further, a plurality of pixel electrodes are arranged in a matrix form in a pixel area defined by the intersection of the gate lines and the data lines. A plurality of thin film transistors that are switched according to a signal of the gate lines to transmit a signal of the data lines to each pixel electrode are formed.
A liquid crystal cell LC is driven by a voltage difference between a pixel electrode that charges a data voltage through a thin film transistor and a common electrode to which a common voltage is applied. The common electrode may be formed on the color filter substrate CFS or on the thin film transistor substrate TFS depending on the types of a liquid crystal display.
In order to enable the display panel LCP to perform an optical function, a top polarizer TPOL may be formed on the front surface of the color filter substrate CFS, and a bottom polarizer BPOL may be formed on the rear surface of the thin film transistor substrate TFS. The top polarizer TPOL and the bottom polarizer BPOL are disposed such that light transmission axes thereof cross orthogonal to each other.
The backlight unit BLU is disposed on the rear surface of the display panel LCP, and includes a light source LA that generates light and a light guide plate LG that guides light from the light source LA to the display panel LCP. A reflection sheet REF is disposed on the rear surface of the light guide plate LG, and an optical sheet is disposed on the front surface of the light guide plate LG. The optical sheet OPT may include a diffusion sheet, a prism sheet, or a protective sheet.
A cover bottom CB is disposed on the bottom of the display panel LCP and the backlight unit BLU. The cover bottom CB needs to be formed in a manner that protects and supports the display panel LCP and the backlight unit BLU.
A driving unit that drives the display panel LCP is provided on at least one end side of the thin film transistor substrate TFS. As illustrated by FIG. 1, the driving unit includes a printed circuit board PCB to drive the display panel LCP, and a drive integrated circuit DIC that is electrically connected to the printed circuit board PCB to supply signals to the display panel LCP. The DIC supplies signals to the gate lines or the data lines through a pad unit formed in the non-display area NA of the thin film transistor substrate TFS. The DIC is mounted on the connection member TP. For example, the connection member TP may be a Tape Carrier Package (TCP), in which one side of the connection member TP is connected to the thin film transistor substrate TFS by Tape Automated Bonding (TAB), and the other side thereof is connected to the PCB.
As such, the driving unit and the LCP are formed separately and electrically connected to each other using the connection member (TP). For this configuration, an additional area where the connection member (TP) is able to be mounted is needed. Such an area increases a non-display area (AA), thereby increasing a bezel area.
For the narrow bezel structure, the printed circuit board PCB is disposed on the rear surface of the thin film transistor substrate TFS. As illustrated in FIG. 2, the PCB may be disposed on the bottom of the cover bottom CB. At this point, a case top CTOP is disposed to cover a edge of the color filter substrate CFS, the non-display area NA of the thin film transistor substrate TFS, and the driving unit.
Even in this case, there is limitation in reducing a bezel area by a connection member TP that connects the thin film transistor substrate TFS and the print circuit board PCB. Specifically, the connection member TP is disposed in a manner of bending along the circumference of an end side of the thin film transistor substrate TFS, and thus, there should be a predetermined distance C between the connection member TP and the thin film transistor substrate TFS. In addition, to prevent damage of the connection member TP having ductility properties, there should be a predetermined distance E between the connection member TP and the case top CTOP. Thus, the general liquid crystal display has a limitation in reducing a bezel area. The bezel area degrades the aesthetic quality of a liquid crystal display, so efforts for reducing the bezel area are needed.